Engineering graphics PPT

1. Orthographic Drawing

2. Multiview Projection
• Projection  a view of an object
• Is a photograph enough to describe an
object?
• A number of views, systematically
arranged...

3. Perspective Projection
Source, at a definite
distance.

4. Orthographic Drawing
Source, at an
infinite distance

5. Four Types of Projection

6. TOP
BOTTOM
FRONT
LEFT RIGHT
REAR
Six Standard Views

7. Six Standard Views

8. Six Standard Views

9. Orthographic Drawing

10. Orthographic
Drawing

11. Orthographic
Drawing

12. Unfolding the
Glass Box
The Glass
Box

13. Top & Right
Side Views

14. Third Angle Projection
Mitter Line
D/2
D/2
D/2 D/2
A transparent
picture plane is
set up between
object and the
station point of an
observer’s eye.
T
F R

15. Third Angle Projection
Mitter line can
only be used
when the
views are
placed
equidistantly.
?????

16. First Angle Projection (Europe & Asia)
Mitter Line
D/2
D/2
D/2 D/2
The observer
looks through the
object to the
planes of
projection.
T
F
R

17. Views of Surfaces
• To effectively create and interpret multiview
projections, you have to consider the elements
that make up most solids:
SURFACES
bounded by straight lines, or curves.

18. Edge View

19. True View

20. Foreshortened View

21. Normal Surface
Parallel to the
plane of projection
(true shape&size)

22. Inclined Surface
Perpendicular
to a plane,
but inclined
or tipped to
adjacent
planes. Edge
vien on perp.
Plane, fs view
on inclined
planes

23. Oblique Surface
Tipped to all planes.
FS on all planes.

24. Normal Edge
True length in
adjacent planes
Point on
perpendicular Plane.

25. Inclined Edge
True length in
parallel plane
(angled)
Shortened on
adjacent planes
(vertical / horizontal)

26. Oblique Edge
Shortened
& Angled
Shortened
& Angled

27. Angles

28. Vertices
•A corner or point, intersection of 3 planes

29. Meaning of a
Point
•A vertex
•Point view of an edge

30. Meaning of a
Line
Visible or hidden:
•An edge (intersection between 2 surfaces)
•Edge view of a surface
•Limiting element of a curved surface

31. Hidden Lines
Dashed hidden lines are used to represent
features that would be hidden behind other
surfaces.

32. Center Lines
Used to indicate symmetrical axes of circles

33. Order of Drawing
•Block out the views
•Locate centerlines
•Start details and arcs first
•Draw dominant details
•Check your views

34. Now : Guess the object....

35. So the Quiz Object....

36. Guess the object....

37. The object .... Is a rectangular prism

38. Guess the object....

39. The object ... Is a cylindrical prism

40. Third Angle Projection...

41. So The Object...

47. THAT’S IT FOR TODAY!
...